From the prior art, a previously used generator with a regulator unit is known. This regulator unit serves to vary an exciter current of a rotor of this generator. This regulator unit has a housing, with which a wiper contact mounting region with a guide and wiper contacts seated therein is integrated. The electronic controller unit and a likewise electronic regulator heat sink are received in a regulator housing portion, and this regulator heat sink is relatively large and extends over large regions between two through openings, which serve to fasten the controller unit to an end plate of the generator. There was a need for a new design of the regulator unit, to improve the cooling of the regulator heat sink.